Functionalized Fe3O4 Nanoparticles Research Articles

A new approach to tailoring the separation characteristics of polyethersulfone nanofiltration membranes by 8-hydroxyquinoline functionalized Fe3O4 nanoparticles

8-Hydroxyquinoline (8-HQ) was used for modification of Fe3O4 nanoparticles (NPs) and preparation of polyethersulfone (PES)-based mixed matrix membranes (MMMs) by phase inversion process. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), Energy dispersive x-ray spectroscopy (EDX), and Field emission scanning electron microscopy (FESEM). The effect of different concentrations of 8-HQ/Fe3O4 NPs into the PES as membrane matrix was investigated by FESEM and atomic force microscopy (AFM). The performance of prepared membranes was evaluated by the water contact angle, pure water flux (PWF), porosity, means pore size, and salt rejection. Bovine serum albumin (BSA) solution was used to investigate the antifouling properties of fabricated membranes. The results showed a decreasing water contact angle from 68.1° for the pristine membrane to 38.3° for M5 at 0.5 wt% 8-HQ/Fe3O4 NPs. The PWF enhanced for all mixed matrix membranes compared with the pristine membrane. The highest PWF (21.5L/m2h) was measured for M4 at 0.2wt% NPs, Wwhile it was 7.1 L/m2h for pristine membrane. Salt rejection improved from 58.55% in M1 (pristine membrane) to 96% in M4 (at 0.2 wt% of 8-HQ/Fe3O4 NPs). Also, the modified membranes showed suitable antifouling property.

Synthesis and characterization of a novel Pyrrole-2-carboxylic acid functionalized magnetic Fe3O4 as a nanocatalyst for synthesis and antibacterial activities of novel isoxazolo[4,3-e]indazole derivatives

Pyrrole-2-carboxylic acid functionalized Fe3O4 nanoparticles as a novel organic–inorganic hybrid heterogeneous catalyst was manufactured and characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR), Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Vibrating sample magnetometer (VSM) techniques. The catalytic activity of the nanomagnetic catalyst was investigated in the new heterocyclic system isoxazolo[4,3-e]indazole was synthesized via the nucleophilic substitution of a hydrogen in 5-nitro-1-p-tolyl-1H-indazole with different 2-phenylacetonitrile derivatives in basic medium. The synthetic compounds exert moderate activity against both Gram positive and Gram negative bacteria and their effectiveness is higher against Bacillus subtilis. This green magnetic nanocatalytic procedure has a good reversibility and provides clean production in a short reaction time.

Preparation and characterization of Cu supported on 2‐(1H‐benzo[d]imidazol‐2‐yl)aniline‐functionalized Fe3O4 nanoparticles as a novel magnetic catalyst for Ullmann and Suzuki cross‐coupling reactions

Copper supported on 2‐(1H‐benzo[d]imidazol‐2‐yl)aniline (BIA)‐functionalized Fe3O4 nanoparticles (Cu‐BIA‐Si‐Fe3O4) as a novel magnetic catalyst was designed and used for the synthesis of new products via Ullmann and Suzuki cross‐coupling reactions. The Ullmann reaction was performed by mixing arylboronic acid with aniline derivatives in dimethylsulfoxide solvent. Also, diaryls were synthesized via Suzuki C–C reactions between aryl halides and phenylboronic acid in the same solvent. The prepared materials and catalyst were characterized with various analytical techniques. The Cu‐BIA‐Si‐Fe3O4 catalyst demonstrated catalytic efficiency with good to excellent yields for both types of reactions in comparison with commercial palladium catalysts. Also, the catalyst could be recovered by a simple filtration and retained its activity even after several cycles.

The influence of carboxylate moieties for efficient loading and pH-controlled release of doxorubicin in Fe3O4 magnetic nanoparticles

One of the significant challenges in a nanoparticles-based anticancer drug delivery system for cancer therapy application is to design nanoparticles with specific functionality for efficient drug conjugation and release. In the present study, different carboxylate molecules, i.e., succinic acid (SA), ascorbic acid (AA), and citric acid (CA), were used as surface modifiers for delivery of an anticancer drug, doxorubicin (DOX), using Fe3O4 magnetic nanoparticles (MNPs). Here, a simple one-pot co-precipitation method was successfully used to fabricate monodisperse and uniform carboxylates functionalized Fe3O4 nanoparticles with excellent superparamagnetic properties and colloidal stabilities. Based on the result, the as-prepared MNPs exhibited high drug loading due to the formation of intermolecular forces between DOX and carboxylates moieties or MNPs surface. Besides, the release of the loaded DOX could quickly be released by simply reducing the pH of the suspension. However, it was observed that both loading efficiency and release of DOX were significantly affected by the type of carboxylate moieties. Finally, in vitro MTT assay of HeLa cell lines also revealed that the as-prepared DOX-loaded nanoparticles were able to induce the death of the cancer cell efficiently.

Response Surface Methodology Approach for Optimized Biodiesel Production from Waste Chicken Fat Oil

Biodiesel is gaining acceptance as an alternative fuel in a scenario where fossil fuel reserves are being depleted rapidly. Therefore, it is considered as the fuel of the future due to its sustainability, renewable nature and environment friendly attributes. The optimal yield of biodiesel from cheap feed stock oils is a challenge to add cost effectiveness without compromising the fuel quality. In the current experiment, waste chicken fat oil was taken as the feedstock oil to produce biodiesel through the chemical and enzymatic route of transesterification. The process of chemical transesterification was performed using KOH and sodium methoxide, while enzymatic transesterification was done by using free Aspergillus terreus lipase and Aspergillus terreus lipase immobilized on functionalized Fe3O4 nanoparticles (Fe3O4_PDA_Lipase) as biocatalysts. The physico-chemical properties of the understudy feedstock oil were analyzed to check the feasibility as a feedstock for the biodiesel synthesis. The feedstock oil was found suitable for biodiesel production based upon quality assessment. Optimization of various reaction parameters (the temperature and time of reaction, catalyst concentration and methanol-to-oil mole ratio) was performed based on the response surface methodology (RSM). The maximum yield of biodiesel (90.6%) was obtained from waste chicken fat oil by using Fe3O4_PDA_Lipase as an immobilized nano-biocatalyst. Moreover, the above said optimum yield was obtained when transesterification was done using 6% Fe3O4_PDA_Lipase with a methanol-to-oil ratio of 6:1 at 42 °C for 36 h. Biodiesel production was monitored by FTIR spectroscopic analysis, whereas compositional profiling was done by GC–MS. The measured fuel properties—cloud point, pour point, flash point, fire point and kinematic viscosity—met the biodiesel specifications by American Society for Testing and Materials (ASTM).

Use of Target-Specific Liposome and Magnetic Nanoparticle Conjugation for the Amplified Detection of Norovirus.

Viral diseases are one of the most life-threatening diseases as they can erupt unpredictably and spread rapidly in any medium with a very small number of particles. Therefore, the key for lethal virus detection should be highly sensitive in the early-stage detection, which can help increase the chance of survival. Amplification of the detecting signal is one of the most promising mechanisms for the detection of low-concentration analytes. A proper amplification can develop such a kind of system where a small number of particles can produce intense signals for a prominent detection. Keeping this in mind, in this report, we have presented a fluorometric method to detect norovirus (NoV) by a newly developed fluorophore-labeled liposome and a magnetically modified Fe3O4 combined system. Homogeneously distributed amine-functionalized liposomes have been constructed filled with a strong fluorophore of calcein. Simultaneously, (3-aminopropyl)-triethoxysilane (APTES)-functionalized Fe3O4 nanoparticles are also synthesized by the standard silanization process, and these two separately synthesized nanoparticles were functionalized with an antibody to achieve specificity. The Fe3O4 and calcein-liposome system has been applied for NoV detection, which was magnetically separated from the analyte medium and then externally burst to release the fluorophores from the core of the liposome. The easiness, rapidity, and sensitivity in a wide linear range can offer a huge potential of this method in point-of-care diagnostics.

Efficiently remove of Cs(I) by metals hexacyanoferrate modified magnetic Fe3O4-chitosan nanoparticles

In order to remove radioactive cesium from wastewater and realize recycling of cesium meanwhile, biopolymer: chitosan functionalized Fe3O4 nanoparticles were synthesized. Chitosan covalently functionalized particles were well dispersed, superparamagnetic and had good stability. Sodium-copper hexacyanoferrate as ion exchanger modified the particles through metal coordination for cesium adsorption. The particles showed good selectivity for Cs(I) and high adsorption capacity (161.3 mg/g). And the desorption rate of Cs(I) could reach up to 99.5%. The relative adsorption capacity still remained 96.6% after the 5th reuse. The results showed the particles were promising for removal of Cs(I) from large-scale waste water.

Rapid Label-Free Isolation of Circulating Tumor Cells from Patients' Peripheral Blood Using Electrically Charged Fe3O4 Nanoparticles.

Isolation of circulating tumor cells (CTCs) in peripheral blood from cancer patients bears critical importance for evaluation of therapeutic efficacy. The current CTC isolation strategies are majorly relying on either protein biomarkers or dimensional features of CTCs. In this study, we present a new methodology for CTC detection and isolation based on the surface charge of cancer cells, a bioelectrical manifestation of the "Warburg effect." Negative surface charge is a direct consequence of glycolysis of cancer cells, which can be utilized as an effective biophysical marker for CTC detection and isolation. Upon cancer cells-nanoparticle interaction via optimum incubation, serum protein-coated electrically charged nanoparticles can trap different cancer cells independent of their epithelial protein expression. In fetal bovine serum , the poly(ethyleneimine)-functionalized Fe3O4 nanoparticles, surface-decorated with protein corona, are able to efficiently capture CTCs from blood samples of colorectal cancer patients. 2-8 CTCshas been isolated from 1 mL of bloodand identified by immunostaining fluorescence in situ hybridization and immunofluorescence staining in all 25 colorectal cancer patients at varied stages, while only 0-1 CTC was detected from blood samples of 10 healthy donors. Diverse CTC subpopulations of heteroploids and biomarker expression can also be detected in this strategy. The label-free, charge-based CTC method shows promise in cancer diagnosis and prognosis paving a new path for liquid biopsy.

Size-modulation of functionalized Fe3O4: nanoscopic customization to devise resolute piezoelectric nanocomposites.

Magnetite (Fe3O4), a representative relaxor multiferroic material, possesses fundamentally appealing multifaceted size-dependent properties. Herein, to evaluate a prototype spinel transition metal oxide (STMO), monodispersed and highly water-dispersible spherical magnetite nanoparticles (MNPs) with an enormous size range (3.7-242.8 nm) were synthesized via a facile microwave-assisted and polyol-mediated solvothermal approach at a controlled temperature and pressure using unique crystallite growth inhibitors. The excellent long-term colloidal stability of the MNPs in a polar environment and increase in their zeta potential confirmed the coordinative effect of the carboxylate groups derived from the covalent surface functionalization, which was also validated by FTIR spectroscopy, TGA and XPS analysis. The optical bandgap (Eg) between the crystal field split-off bands, which was calculated using the absorption spectra, increased gradually with a decrease in size of the MNPs within a broad UV-Vis range (1.59-4.92 eV). The red-shifting of the asymmetric Raman peaks with a smaller size and short-range electron-phonon coupling could be explained by the modified phonon confinement model (MPCM), whereas ferrimagnetic nature rejigged by superparamagnetism was verified from Mössbauer analysis. These stoichiometric, non-toxic, polar and magnetic nanocrystals are not only ideal for biomedical applications, but also suitable as electroactive porous host networks. Finally, the size-modulated MNPs were incorporated in poly(vinylidene fluoride) [PVDF]-based polytype nanogenerators as an electret filler to demonstrate their piezoelectric performance (VOC∼115.95 V and ISC∼1.04 μA), exhibiting substantial electromagnetic interference shielding.

AMPK-mediated senolytic and senostatic activity of quercetin surface functionalized Fe3O4 nanoparticles during oxidant-induced senescence in human fibroblasts

Cellular senescence may contribute to aging and age-related diseases and senolytic drugs that selectively kill senescent cells may delay aging and promote healthspan. More recently, several categories of senolytics have been established, namely HSP90 inhibitors, Bcl-2 family inhibitors and natural compounds such as quercetin and fisetin. However, senolytic and senostatic potential of nanoparticles and surface-modified nanoparticles has never been addressed. In the present study, quercetin surface functionalized Fe3O4 nanoparticles (MNPQ) were synthesized and their senolytic and senostatic activity was evaluated during oxidative stress-induced senescence in human fibroblasts in vitro. MNPQ promoted AMPK activity that was accompanied by non-apoptotic cell death and decreased number of stress-induced senescent cells (senolytic action) and the suppression of senescence-associated proinflammatory response (decreased levels of secreted IL-8 and IFN-β, senostatic action). In summary, we have shown for the first time that MNPQ may be considered as promising candidates for senolytic- and senostatic-based anti-aging therapies.

Efficient extraction of uranium from environmental samples using phosphoramide functionalized magnetic nanoparticles: Understanding adsorption and binding mechanisms

Phosphoramide functionalized Fe3O4 nanoparticles (NPs) were synthesized by a three step procedure and its application for uranium extraction from different enviornmental matrices has been demonstrated. A maximum adsorption capacity of 95.2 mg of U/g of the sorbent has been achieved which is higher as compared to many reported magnetic NPs. pH dependent adsorption studies were performed at 1 ppm uranium concentrations which suggests more than 80% adsorption in pH range of 4–8 with maximum adsorption at pH 6. Interestingly this is the pH range of most naturally occurring water bodies suggesting the potential of this material to extract uranium from real environmental samples. Adsorption studies were carried out with tap water, drinking water and sea water and more than 90% uranium extraction was observed. Desorption studies were performed with different reagents suggesting that the material can be reused again. EXAFS studies have been carried out which suggests that the uranium binds with oxygens of three PO group at the surface of phosphoramide functionalized NPs and based on this, binding mode of uranium with the synthesized sorbent is proposed.

Preparation of magnetic conjugated microporous polymers for highly efficient removal of dye from water

AbstractBACKGROUNDA magnetic conjugated microporous polymer (MCMP) composite was designed with bromo groups of CMP and amino groups on the surface of Fe3O4 nanoparticles that acted as promising adsorbents for wastewater treatment. Fe3O4 nanoparticles were successfully bonded on the predesigned CMP material to form the MCMP by means of a new and simple nucleophilic substitution reaction in organic media.RESULTSThe MCMP could be separated by applying an external magnetic field because of the Fe3O4 nanoparticles. It exhibited sufficient dye adsorption for methylene blue (MB) with a high sorption capability of 869.43 mg g−1 in aqueous solutions. The recovery and reusability of MCMP were >70% after six cycles of desorption and regeneration, indicating that the MCMP had excellent cycle stability. The magnetization saturation strength of MCMP was 13.5 emu g−1 which was sufficient to be magnetically separated from wastewater using artificial magnetic fields.CONCLUSIONThe MCMP possessed excellent adsorption capacity and dispersibility, and good recyclability after banded with functionalized Fe3O4 nanoparticles. The excellent properties of MCMP indicated that it could be used as an adsorbent with great application potential for quick separation of water pollutants such as dyes in wastewater treatment. © 2019 Society of Chemical Industry

Chlorosulfonic Acid Supported Piperidine-4-carboxylic Acid (PPCA) Functionalized Fe3O4 Nanoparticles (Fe3O4-PPCA): The Efficient, Green and Reusable Nanocatalyst for the Synthesis of Pyrazolyl Coumarin Derivatives under Solvent-Free Conditions.

In this study, we developed a convenient methodology for the synthesis of coumarin linked to pyrazolines and pyrano [2,3-h] coumarins linked to 3-(1,5-diphenyl-4,5- dihydro-1H-pyrazol-3-yl)-chromen-2-one derivatives using Chlorosulfonic acid supported Piperidine-4-carboxylic acid (PPCA) functionalized Fe3O4 nanoparticles (Fe3O4-PPCA) catalyst. Fe3O4-PPCA was investigated as an efficient and magnetically recoverable Nanocatalyst for the one-pot synthesis of substituted coumarins from the reaction of coumarin with a variety of aromatic aldehydes in high to excellent yield at room temperature under solvent-free conditions. The magnetic nanocatalyst can be easily recovered by applying an external magnet device and reused for at least 10 reaction runs without considerable loss of reactivity. The advantages of this protocol are the use of commercially available materials, simple and an inexpensive procedure, easy separation, and an eco-friendly procedure, and it shows good reaction times, good to high yields, inexpensive and practicability procedure, and high efficiency.

Pd(II) supported dioxime functionalized Fe3O4 nanoparticles as efficient, eco-friendly and reusable catalysts for the Suzuki-Miyaura cross-coupling reaction in water

Five novel dioxime ligands (L(1-5)H2) were synthesized in various yields under suitable conditions. Novel nano-Fe3O4-supported compounds (Fe3O4/L(1-5)) based on dioxime ligands were also prepared. Subsequently, hybrid materials Fe3O4/L(1-5)/Pd(II) were fabricated by the reaction of Fe3O4/L(1-5) with Pd(AcO)2 in acetonitrile. All synthesized nanoparticles were characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray analysis (EDX), X-ray diffraction (XRD), inductively coupled plasma analysis (ICP), differential scanning calorimetry (DTA), and thermogravimetric analysis (TGA). The spectroscopic results show that the magnetite (Fe3O4) nanoparticles are in nano size since crystal sizes are < 100 nm. The particles have an average size of about 9.4–23.3 nm. The powder XRD confirmed that the synthesized Fe3O4, Fe3O4/L(1-5), and Fe3O4/L(1-5)/Pd(II) MNPs possess cubic structure having the lattice parameter between 8.31 and 8.40 Å. The structure and the lattice parameters are in good agreement with the literature reported data. The Fe3O4/L(1-5)/Pd(II) nanocatalysts showed high activities in the Suzuki-Miyaura cross-coupling of different aryl halides including iodides, bromides and even chlorides with phenylboronic acid under green and aerobic conditions. More importantly, the reusability experiments revealed that Fe3O4/L(1-5)/Pd(II) catalysts were durable by almost maintaining their inherent activity after 5 catalytic cycles.

Disperse magnetic sources constructed with functionalized Fe3O4 nanoparticles in poly-l-lactic acid scaffolds

Fe3O4 nanoparticles were widely applied as magnetic sources in scaffolds to stimulate bone regeneration. In this study, Fe3O4 nanoparticles were successfully functionalized by oleic acid to circumvent the aggregate issue of the nanoparticles in poly-l-lactic acid (PLLA) bone scaffolds fabricated via selective laser sintering. On the one hand, carboxylic acid groups of oleic acid may interact with the hydroxyl groups of Fe3O4 nanoparticles in case of aqueous medium, contributing to the surface functionalization of the nanoparticles. On the other hand, hydrocarbon chains of oleic acid were oriented toward the PLLA matrix and mutually exclusive, facilitating the dispersion of the nanoparticles in PLLA scaffolds. As a result, the dispersion of functionalized Fe3O4 nanoparticles in scaffold was significantly better than that of non-functionalized nanoparticles. The magnetic scaffolds with uniformly dispersed nanoparticles (12 wt%) presented increased compressive strength and modulus by 95% and 68%, respectively, owning to the rigid enhancement effect of nanoparticles. Meanwhile, they exhibited good capabilities of cell adhesion, proliferation and differentiation, due to the magnetic stimulation for cells produced by uniformly dispersed magnetic sources. All these positive results indicated that the magnetic scaffolds showed great potential in the application of bone regeneration.

Phytic acid functionalized Fe3O4 nanoparticles loaded with Ti(IV) ions for phosphopeptide enrichment in mass spectrometric analysis.

A novel magnetic nanomaterial for use in metal ion based affinity chromatography is described. It is based on the chelation between the phosphate groups of phytic acid (PA) and Ti(IV) ions. Due to the large number (6) of phosphate groups of PA, it has a large capacity for Ti(IV) ions. PA was first immobilized on magnetite nanoparticles (PA-MNPs) and then loaded with Ti(IV) ions to obtain the sorbent (Ti-PA-MNPs). The fraction of Ti(IV) ions on the surface of PA-MNPs that is exposed to the solution binds the phosphate groups of phosphopeptides. The bound phosphopeptides can then be magnetically separated. The method was applied to the enrichment of the phosphopeptides in a β-casein tryptic digest. A tryptic digest of bovine serum albumin (BSA) was added at a molar ratio (β-casein to BSA) of 1:2000 to study selectivity. The phosphopeptides were quantified by mass spectrometry. The limit of detection can be as low as 8 × 10-10molL-1. This sorbent has a high absorption capacity (53.5μgmg-1) and shows good recoveries (90%). As many as 2145 phosphopeptides were isolated from 500μg tryptic digest of a rat liver lysate after enrichment by Ti-PA-MNPs. This is superior to that (1568 phosphopeptides) of commercial TiO2 kit. Graphical abstract Schematic presentation of fabrication for a novel modified magnetic nanomaterial (Ti-PA-MNPs) based on the chelation of phytic acid (PA) with Ti(IV) ions. Ti-PA-MNPs were successfully applied to enriching low abundance phosphopeptides from biosamples in mass spectrometric analysis.

A recyclable biointerface based on cross-linked branched DNA nanostructures for ultrasensitive nucleic acid detection

The detection of specific nucleic acids is becoming increasingly important in the discovery of genetic diseases and clinical molecular diagnostics. Here we report a DNA nanostructure-based platform which enables a recyclable biointerface for ultra-sensitive detection of nucleic acid. We created a chemically cross-linked branched DNA nanostructure (CCLB-DNA) as the probe DNA to engineer the biointerfaces, thereby increasing probe distance, exposing more DNA probes from the interface into the solution phase, and thus enhancing the signal dramatically. In addition, DNA functionalized Fe3O4 nanoparticles were utilized for further signal amplification. The detection limit could go as low as 500 fM. Moreover, CCLB-DNA could endure denaturation conditions without disruption of duplex integrity; as a result, the recognition layer could be easily regenerated and the biointerface could be reused. Our CCLB-DNA represents an excellent prospect in the engineering of recyclable biointerface, which will be beneficial to many biosensing systems.

Supported 4-carboxybenzyl sulfamic acid on magnetic nanoparticles as a recoverable and recyclable catalyst for synthesis of 3,4,5-trisubstituted furan-2(5H)-one derivatives

4-Carboxybenzyl sulfamic acid functionalized Fe3O4 nanoparticles as a novel catalyst was manufactured. This catalyst was characterized and evaluated in the one-pot synthesis of furan-2(5H)-one derivatives from dimethyl acetylenedicarboxylate, aryl aldehydes, and various anilines in terms of activity and reusability. The catalyst showed high catalytic activity, good recoverability and reusability, thermal stability and provides clean production of fine furan-2(5H)-one derivatives in short reaction times. The heterogeneous catalyst could be used at least five times without significant loss of its activity.

Membrane bioreactors troubleshooting through the preparation of a high antifouling PVDF ultrafiltration mixed-matrix membrane blended with O-carboxymethyl chitosan-Fe3O4 nanoparticles

ABSTRACTPolymeric ultrafiltration (UF) membranes often used in membrane bioreactor (MBR) prone to be fouled by fouling agents. Therefore, in this paper, the antifouling characteristics of polyvinylidene fluoride (PVDF) UF membranes for wastewater treatment are improved through modifying membranes by O-carboxymethyl chitosan (OCMCS)-functionalized Fe3O4 nanoparticles (OCMCSFe3O4). The modifier agent was manufactured by the adsorption of OCMCS on Fe3O4 nanoparticles, which were synthesized via co-precipitating method. Antifouling performance of membranes was assessed by permeation tests done using activated sludge suspension as a biological foulant, then the calculation of the pure water flux recovery ratio (FRR) and fouling resistance parameters. Also, to investigate the protein rejection of membranes, permeation tests were conducted by the bovine serum albumin (BSA) solution. According to the obtained results, surface hydrophilicity of the embedded membranes was improved in the low concentrations of the modified nanoparticles. However, the high quantity of the OCMCS-Fe3O4 nanoparticles (>0.1 wt. %) in the casting solution lessened membrane performance owing to the agglomeration of the nanoparticles in the polymer matrix. Although, the 1 wt. % OCMCS-Fe3O4 membrane revealed considerably higher PWF and permeation than that of the other membranes. It was because of defects and cracks in the membranes. The 0.05 wt. % OCMCS-Fe3O4/PVDF membrane exhibited the highest FRR (95.7%) and protein rejection value (48%) and the lowest irreversible fouling resistance (Rir) value (4.2%). It is concluded that the blended membranes with modified nanoparticles resulted in a high-flux ultrafiltration membrane comparable with microfiltration membrane, while its separation properties remained similar to UF membrane.

Highly sensitive fluorescent detection of p53 protein based on DNA functionalized Fe3O4 nanoparticles

The accurate quantification of p53 protein expression level is of great importance for cancer diagnosis. Here, a highly sensitive fluorescent sensor based on DNA functionalized magnetic nanoparticles was developed for the detection of p53 protein expression. Instead of a monoclonal antibody, a consensus DNA was employed to capture p53 protein. Meanwhile the fluorescent dye tethered DNA was used as the signal output instead of enzyme tagged nanoparticle or antibody. Consequently, our developed method is cost-effective for both the p53 capture and detection by compared with the conventional immunoassay. The biosensor developed by the above strategy was used to quantitatively detect p53, which yields a detection limit of 8 p.M. with the linear range of 50 p.M. to 2 nM. The sensitive for specific p53 detection was achieved due to the facile magnetic separation from the complex condition, and the reduced non-specific absorption effect by dextran. Moreover, the method is able to measure p53 from real cell lysate without extensive sample pretreatment/separation. The developed p53 biosensor has high sensitivity, good selectivity and reliable accuracy. It demonstrates great potential in clinical cancer diagnosis and early detection of cancer.